用 hooks 拦截和控制智能体行为

import asyncio
from claude_agent_sdk import (
    AssistantMessage,
    ClaudeSDKClient,
    ClaudeAgentOptions,
    HookMatcher,
    ResultMessage,
)


# 定义接收工具调用细节的 hook 回调
async def protect_env_files(input_data, tool_use_id, context):
    # 从工具的输入参数里提取文件路径
    file_path = input_data["tool_input"].get("file_path", "")
    file_name = file_path.split("/")[-1]

    # 目标是 .env 文件时阻止该操作
    if file_name == ".env":
        return {
            "hookSpecificOutput": {
                "hookEventName": input_data["hook_event_name"],
                "permissionDecision": "deny",
                "permissionDecisionReason": "Cannot modify .env files",
            }
        }

    # 返回空对象以允许该操作
    return {}


async def main():
    options = ClaudeAgentOptions(
        hooks={
            # 为 PreToolUse 事件注册 hook
            # 匹配器只过滤出 Write 和 Edit 工具调用
            "PreToolUse": [HookMatcher(matcher="Write|Edit", hooks=[protect_env_files])]
        }
    )

    async with ClaudeSDKClient(options=options) as client:
        await client.query("Create a .env file with the standard local development database configuration")

        async for message in client.receive_response():
            # 过滤出助手和结果消息
            if isinstance(message, (AssistantMessage, ResultMessage)):
                print(message)


asyncio.run(main())

import { query, HookCallback, PreToolUseHookInput } from "@anthropic-ai/claude-agent-sdk";

// 用 HookCallback 类型定义 hook 回调
const protectEnvFiles: HookCallback = async (input, toolUseID, { signal }) => {
  // 把 input 转成具体的 hook 类型以获得类型安全
  const preInput = input as PreToolUseHookInput;

  // 转换 tool_input 以访问它的属性（在 SDK 里类型为 unknown）
  const toolInput = preInput.tool_input as Record<string, unknown>;
  const filePath = toolInput?.file_path as string;
  const fileName = filePath?.split("/").pop();

  // 目标是 .env 文件时阻止该操作
  if (fileName === ".env") {
    return {
      hookSpecificOutput: {
        hookEventName: preInput.hook_event_name,
        permissionDecision: "deny",
        permissionDecisionReason: "Cannot modify .env files"
      }
    };
  }

  // 返回空对象以允许该操作
  return {};
};

for await (const message of query({
  prompt: "Create a .env file with the standard local development database configuration",
  options: {
    hooks: {
      // 为 PreToolUse 事件注册 hook
      // 匹配器只过滤出 Write 和 Edit 工具调用
      PreToolUse: [{ matcher: "Write|Edit", hooks: [protectEnvFiles] }]
    }
  }
})) {
  // 过滤出助手和结果消息
  if (message.type === "assistant" || message.type === "result") {
    console.log(message);
  }
}

options = ClaudeAgentOptions(
    hooks={"PreToolUse": [HookMatcher(matcher="Bash", hooks=[my_callback])]}
)

async with ClaudeSDKClient(options=options) as client:
    await client.query("Your prompt")
    async for message in client.receive_response():
        print(message)

for await (const message of query({
  prompt: "Your prompt",
  options: {
    hooks: {
      PreToolUse: [{ matcher: "Bash", hooks: [myCallback] }]
    }
  }
})) {
  console.log(message);
}

async def async_hook(input_data, tool_use_id, context):
    # 启动后台任务，然后立即返回
    asyncio.create_task(send_to_logging_service(input_data))
    return {"async_": True, "asyncTimeout": 30000}

const asyncHook: HookCallback = async (input, toolUseID, { signal }) => {
  // 启动后台任务，然后立即返回
  sendToLoggingService(input).catch(console.error);
  return { async: true, asyncTimeout: 30000 };
};

async def redirect_to_sandbox(input_data, tool_use_id, context):
    if input_data["hook_event_name"] != "PreToolUse":
        return {}

    if input_data["tool_name"] == "Write":
        original_path = input_data["tool_input"].get("file_path", "")
        return {
            "hookSpecificOutput": {
                "hookEventName": input_data["hook_event_name"],
                "permissionDecision": "allow",
                "updatedInput": {
                    **input_data["tool_input"],
                    "file_path": f"/sandbox{original_path}",
                },
            }
        }
    return {}

const redirectToSandbox: HookCallback = async (input, toolUseID, { signal }) => {
  if (input.hook_event_name !== "PreToolUse") return {};

  const preInput = input as PreToolUseHookInput;
  const toolInput = preInput.tool_input as Record<string, unknown>;
  if (preInput.tool_name === "Write") {
    const originalPath = toolInput.file_path as string;
    return {
      hookSpecificOutput: {
        hookEventName: preInput.hook_event_name,
        permissionDecision: "allow",
        updatedInput: {
          ...toolInput,
          file_path: `/sandbox${originalPath}`
        }
      }
    };
  }
  return {};
};

async def block_etc_writes(input_data, tool_use_id, context):
    file_path = input_data["tool_input"].get("file_path", "")

    if file_path.startswith("/etc"):
        return {
            # 顶层字段：显示给用户的消息
            "systemMessage": "Remember: system directories like /etc are protected.",
            # hookSpecificOutput：阻止该操作
            "hookSpecificOutput": {
                "hookEventName": input_data["hook_event_name"],
                "permissionDecision": "deny",
                "permissionDecisionReason": "Writing to /etc is not allowed",
            },
        }
    return {}

const blockEtcWrites: HookCallback = async (input, toolUseID, { signal }) => {
  const preInput = input as PreToolUseHookInput;
  const toolInput = preInput.tool_input as Record<string, unknown>;
  const filePath = toolInput?.file_path as string;

  if (filePath?.startsWith("/etc")) {
    return {
      // 顶层字段：显示给用户的消息
      systemMessage: "Remember: system directories like /etc are protected.",
      // hookSpecificOutput：阻止该操作
      hookSpecificOutput: {
        hookEventName: preInput.hook_event_name,
        permissionDecision: "deny",
        permissionDecisionReason: "Writing to /etc is not allowed"
      }
    };
  }
  return {};
};

async def auto_approve_read_only(input_data, tool_use_id, context):
    if input_data["hook_event_name"] != "PreToolUse":
        return {}

    read_only_tools = ["Read", "Glob", "Grep"]
    if input_data["tool_name"] in read_only_tools:
        return {
            "hookSpecificOutput": {
                "hookEventName": input_data["hook_event_name"],
                "permissionDecision": "allow",
                "permissionDecisionReason": "Read-only tool auto-approved",
            }
        }
    return {}

const autoApproveReadOnly: HookCallback = async (input, toolUseID, { signal }) => {
  if (input.hook_event_name !== "PreToolUse") return {};

  const preInput = input as PreToolUseHookInput;
  const readOnlyTools = ["Read", "Glob", "Grep"];
  if (readOnlyTools.includes(preInput.tool_name)) {
    return {
      hookSpecificOutput: {
        hookEventName: preInput.hook_event_name,
        permissionDecision: "allow",
        permissionDecisionReason: "Read-only tool auto-approved"
      }
    };
  }
  return {};
};

options = ClaudeAgentOptions(
    hooks={
        "PreToolUse": [
            HookMatcher(hooks=[authorization_check]),
            HookMatcher(hooks=[input_validator]),
            HookMatcher(hooks=[audit_logger]),
        ]
    }
)

const options = {
  hooks: {
    PreToolUse: [
      { hooks: [authorizationCheck] },
      { hooks: [inputValidator] },
      { hooks: [auditLogger] }
    ]
  }
};

options = ClaudeAgentOptions(
    hooks={
        "PreToolUse": [
            # 匹配文件修改工具
            HookMatcher(matcher="Write|Edit|NotebookEdit", hooks=[file_security_hook]),
            # 匹配所有 MCP 工具
            HookMatcher(matcher="^mcp__", hooks=[mcp_audit_hook]),
            # 匹配一切（没有匹配器）
            HookMatcher(hooks=[global_logger]),
        ]
    }
)

const options = {
  hooks: {
    PreToolUse: [
      // 匹配文件修改工具
      { matcher: "Write|Edit|NotebookEdit", hooks: [fileSecurityHook] },
      // 匹配所有 MCP 工具
      { matcher: "^mcp__", hooks: [mcpAuditHook] },
      // 匹配一切（没有匹配器）
      { hooks: [globalLogger] }
    ]
  }
};

async def subagent_tracker(input_data, tool_use_id, context):
    # 子智能体结束时记录它的细节
    print(f"[SUBAGENT] Completed: {input_data['agent_id']}")
    print(f"  Transcript: {input_data['agent_transcript_path']}")
    print(f"  Tool use ID: {tool_use_id}")
    print(f"  Stop hook active: {input_data.get('stop_hook_active')}")
    return {}


options = ClaudeAgentOptions(
    hooks={"SubagentStop": [HookMatcher(hooks=[subagent_tracker])]}
)

import { HookCallback, SubagentStopHookInput } from "@anthropic-ai/claude-agent-sdk";

const subagentTracker: HookCallback = async (input, toolUseID, { signal }) => {
  // 转成 SubagentStopHookInput 以访问子智能体专属字段
  const subInput = input as SubagentStopHookInput;

  // 子智能体结束时记录它的细节
  console.log(`[SUBAGENT] Completed: ${subInput.agent_id}`);
  console.log(`  Transcript: ${subInput.agent_transcript_path}`);
  console.log(`  Tool use ID: ${toolUseID}`);
  console.log(`  Stop hook active: ${subInput.stop_hook_active}`);
  return {};
};

const options = {
  hooks: {
    SubagentStop: [{ hooks: [subagentTracker] }]
  }
};

import asyncio
import json
import urllib.request
from datetime import datetime


def _send_webhook(tool_name):
    """把工具使用数据 POST 到外部 webhook 的同步辅助函数。"""
    data = json.dumps(
        {
            "tool": tool_name,
            "timestamp": datetime.now().isoformat(),
        }
    ).encode()

    req = urllib.request.Request(
        "https://api.example.com/webhook",
        data=data,
        headers={"Content-Type": "application/json"},
        method="POST",
    )
    urllib.request.urlopen(req)


async def webhook_notifier(input_data, tool_use_id, context):
    # 只在工具完成之后触发（PostToolUse），不是之前
    if input_data["hook_event_name"] != "PostToolUse":
        return {}

    try:
        # 在线程里运行阻塞的 HTTP 调用，避免阻塞事件循环
        await asyncio.to_thread(_send_webhook, input_data["tool_name"])
    except Exception as e:
        # 记录错误但不抛出
        print(f"Webhook request failed: {e}")

    return {}

import { query, HookCallback, PostToolUseHookInput } from "@anthropic-ai/claude-agent-sdk";

const webhookNotifier: HookCallback = async (input, toolUseID, { signal }) => {
  // 只在工具完成之后触发（PostToolUse），不是之前
  if (input.hook_event_name !== "PostToolUse") return {};

  try {
    await fetch("https://api.example.com/webhook", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({
        tool: (input as PostToolUseHookInput).tool_name,
        timestamp: new Date().toISOString()
      }),
      // 传入 signal，使 hook 超时时请求被取消
      signal
    });
  } catch (error) {
    // 把取消与其他错误分开处理
    if (error instanceof Error && error.name === "AbortError") {
      console.log("Webhook request cancelled");
    }
    // 不要重新抛出
  }

  return {};
};

// 注册为 PostToolUse hook
for await (const message of query({
  prompt: "Refactor the auth module",
  options: {
    hooks: {
      PostToolUse: [{ hooks: [webhookNotifier] }]
    }
  }
})) {
  console.log(message);
}

import asyncio
import json
import urllib.request

from claude_agent_sdk import ClaudeSDKClient, ClaudeAgentOptions, HookMatcher


def _send_slack_notification(message):
    """经传入 webhook 向 Slack 发消息的同步辅助函数。"""
    data = json.dumps({"text": f"Agent status: {message}"}).encode()

    req = urllib.request.Request(
        "https://hooks.slack.com/services/YOUR/WEBHOOK/URL",
        data=data,
        headers={"Content-Type": "application/json"},
        method="POST",
    )
    urllib.request.urlopen(req)


async def notification_handler(input_data, tool_use_id, context):
    try:
        # 在线程里运行阻塞的 HTTP 调用，避免阻塞事件循环
        await asyncio.to_thread(_send_slack_notification, input_data.get("message", ""))
    except Exception as e:
        print(f"Failed to send notification: {e}")

    # 返回空对象。Notification hooks 不修改智能体行为
    return {}


async def main():
    options = ClaudeAgentOptions(
        hooks={
            # 为 Notification 事件注册 hook（不需要匹配器）
            "Notification": [HookMatcher(hooks=[notification_handler])],
        },
    )

    async with ClaudeSDKClient(options=options) as client:
        await client.query("Analyze this codebase")
        async for message in client.receive_response():
            print(message)


asyncio.run(main())

import { query, HookCallback, NotificationHookInput } from "@anthropic-ai/claude-agent-sdk";

// 定义把通知发到 Slack 的 hook 回调
const notificationHandler: HookCallback = async (input, toolUseID, { signal }) => {
  // 转成 NotificationHookInput 以访问 message 字段
  const notification = input as NotificationHookInput;

  try {
    // 把通知消息 POST 到 Slack 传入 webhook
    await fetch("https://hooks.slack.com/services/YOUR/WEBHOOK/URL", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({
        text: `Agent status: ${notification.message}`
      }),
      // 传入 signal，使 hook 超时时请求被取消
      signal
    });
  } catch (error) {
    if (error instanceof Error && error.name === "AbortError") {
      console.log("Notification cancelled");
    } else {
      console.error("Failed to send notification:", error);
    }
  }

  // 返回空对象。Notification hooks 不修改智能体行为
  return {};
};

// 为 Notification 事件注册 hook（不需要匹配器）
for await (const message of query({
  prompt: "Analyze this codebase",
  options: {
    hooks: {
      Notification: [{ hooks: [notificationHandler] }]
    }
  }
})) {
  console.log(message);
}

const myHook: HookCallback = async (input, toolUseID, { signal }) => {
  const preInput = input as PreToolUseHookInput;
  const toolInput = preInput.tool_input as Record<string, unknown>;
  const filePath = toolInput?.file_path as string;
  if (!filePath?.endsWith(".md")) return {}; // 跳过非 markdown 文件

  // 处理 markdown 文件...
  return {};
};

return {
  hookSpecificOutput: {
    hookEventName: "PreToolUse",
    permissionDecision: "allow",
    updatedInput: { command: "new command" }
  }
};

options = ClaudeAgentOptions(
    setting_sources=["project"],  # 加载含 hooks 的 .claude/settings.json
)

const options = {
  settingSources: ["project"] // 加载含 hooks 的 .claude/settings.json
};